I don’t think I’ve seen notifications for World Energy being full in quite a while. And when I did used to get them, it seemed random to me — it didn’t seem like I got one every time my energy was full, just every now and then.
It seems like the notifications are all a bit random, or possibly have a cooldown timer. I get messages about my base being attacked, but I definitely don’t get one for every time I’m raided.
It might be the case that the game limits how often it will send you a notification, and which one it sends isn’t consistent.
It’s been suggested before that notifications should be more customizable, which you might want to vote for: